This invention relates to the field of door security systems. More specifically, this invention relates to the use of a push or exit bar for securing a doorway.
Push bars or exit bars which allow egress through a doorway while limiting ingress are well-known components of door security and emergency systems. The conventional exit bar is mounted on the interior side of the door to be secured and is oriented generally horizontally across the face of the door. A push force on the bar toward the door face operates a door latch to permit opening of the door. Conventional exit bars typically employ a mechanical linkage to actuate the latch mechanism for unlatching the door. Exit bars may also employ mechanical locks to secure the door from opening. A handle can be additionally provided on the exterior face of the door to allow ingress under certain circumstances. Exit bars have also been connected with alarm systems to warn security personnel of a door opening.
Conventional exit bar systems while enjoying great popularity have also exhibited a number of deficiencies. For example, to secure an exit bar from operating the associated latch may require individually manually locking each bar. For most applications, it is generally undesirable for safety reasons to permanently lock exit bars. Even when a building has low occupancy, there may be times when for emergency reasons, exit doors should not be secured in a permanent fashion that would inhibit egress.
During periods of high traffic levels through a doorway, mechanical latch mechanisms of a conventional exit bar can experience a high rate of wear. To reduce wear on mechanical latch components, some conventional exit bars may be manually locked in a dogged position wherein the latches remain in a retracted state. However, each bar must be directly manually dogged and undogged at the site of the door.